Skip to Main Content
GEOREF RECORD

Strike-parallel variations in clay minerals and fault vergence in the Cascadia subduction zone

Michael B. Underwood
Strike-parallel variations in clay minerals and fault vergence in the Cascadia subduction zone
Geology (Boulder) (February 2002) 30 (2): 155-158

Abstract

Clay minerals probably affect the zonation of mechanical properties within a thick unit of abyssal-plain deposits as they enter the Cascadia subduction zone. Landward-vergent thrust faults develop above a deeper decollement because smectite-rich mudrocks within that corridor release more water during clay dehydration, which in turn elevates pore pressure and reduces basal shear stress relative to wedge strength. Conversely, dilution of smectite by illite and chlorite increases the frictional coefficient, and fluid overpressure should drop where smectite dehydration is volumetrically reduced. Thus, thrust faults within chlorite-rich segments of the margin are seaward vergent.


ISSN: 0091-7613
EISSN: 1943-2682
Coden: GLGYBA
Serial Title: Geology (Boulder)
Serial Volume: 30
Serial Issue: 2
Title: Strike-parallel variations in clay minerals and fault vergence in the Cascadia subduction zone
Affiliation: University of Missouri at Columbia, Department of Geological Sciences, Columbia, MO, United States
Pages: 155-158
Published: 200202
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 30
Accession Number: 2002-014646
Categories: Solid-earth geophysicsOceanography
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. sketch maps
N44°40'26" - N44°40'32", W125°07'09" - W125°07'05"
N44°53'30" - N44°53'30", W126°20'48" - W126°20'48"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2019, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 200206
Program Name: ODPOcean Drilling Program
Program Name: DSDPDeep Sea Drilling Project
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal